This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This is a clinical study focused on management of physical and psychological symptoms to enhance the quality of life remaining for individuals who are nearing the end of their lives. The specific aim is to learn whether the hallucinogen, psilocybin, might be effective in reducing anxiety, depression and physical pain, and improving the quality of life in terminal cancer patients. 12 adult subjects with cancer with projected survival up to one year and anxiety disorder will be screened and given informed consent. This pilot investigation is a double-blind, placebo-controlled study with a crossover design. All subjects will receive 0.2 mg/kg of psilocybin during one treatment session and an active placebo, 250 mg of niacin, during a second session six weeks later, in a randomized sequence. The principal investigator and a master's level psychoterapist or nurse will remain with the subject until the effects of the drug have subsided. Efficacy will be evaluated by a variety of pre- and post-measures examining anxiety, depression, pain and quality of life.